Water tank



FIG. 1 is a front, left, top perspective view of a water tank showingour new design;

FIG. 2 is a front, left, bottom perspective view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a front elevation view thereof; and,

FIG. 6 is an enlarged perspective view of the top handle feature shownin FIG. 1.

The broken lines in the drawings depict portions of the water tank thatform no part of the claimed design.

CLAIM The ornamental design for a water tank, as shown and described. 